1. Field of the Invention
The present invention relates to a complex polyester composition and a lubricant. Specifically, the present invention relates to a complex polyester composition containing specific polyester, and a lubricant containing the complex polyester composition.
2. Description of the Related Art
In general, a lubricant contains base oil and various additives. Examples of the base oil include mineral oil obtained from crude oil, ester-based oil which is chemically synthesized, fluorine oil, polyalphaolefin-based oil, and the like. Among them, the ester-based oil is preferably used in a jet plane, automobile engine oil, grease, and the like from the viewpoints of a low fluid point, a high viscosity index, a high flash point, excellent lubrication performance, biodegradability, and the like.
Various esters such as monoester obtained from a reaction between an aliphatic monocarboxylic acid and monohydric alcohol; diester obtained from a reaction between an aliphatic dibasic acid and monohydric alcohol; ester obtained from a reaction between polyhydric alcohol and an aliphatic carboxylic acid; and complex ester obtained from a reaction between polyol, a polybasic acid, and an aliphatic monocarboxylic acid, have been disclosed as the ester-based oil (JP2002-097482A, JP2005-154726A, JP2005-232434A, JP2005-213377A, and JP2005-232470A).
In addition, in JP2007-217414A, JP1996-208814A (JP-H08-208814A), and JP2011-89106A, a polyester composition obtained from a reaction between an aliphatic dibasic acid and polyol is disclosed. In JP2007-217414A, ester obtained from a reaction between polyol and an aliphatic diacid dimer is disclosed. Here, ester to be obtained is used as a cosmetic composition.
In addition, in JP1996-208814A (JP-H08-208814A), ester obtained from a reaction between polyol, a fatty acid, and a dibasic acid is disclosed, and in JP2011-89106A, ester obtained from a reaction between polyol, a dibasic acid, and monohydric alcohol is disclosed. In this literature, ester to be obtained is able to be used as a lubricant composition and is able to exhibit excellent lubrication performance.